Folate and vitamin B6 from diet and supplements in relation to risk of coronary heart disease among women.
BACKGROUND
Hyperhomocysteinemia is caused by genetic and lifestyle influences, including low intakes of folate and vitamin B6. However, prospective data relating intake of these vitamins to risk of coronary heart disease (CHD) are not available.


OBJECTIVE
To examine intakes of folate and vitamin B6 in relation to the incidence of nonfatal myocardial infarction (MI) and fatal CHD.


METHODS
Prospective cohort study.


METHODS
In 1980, a total of 80082 women from the Nurses' Health Study with no previous history of cardiovascular disease, cancer, hypercholesterolemia, or diabetes completed a detailed food frequency questionnaire from which we derived usual intake of folate and vitamin B6.


METHODS
Nonfatal MI and fatal CHD confirmed by World Health Organization criteria.


RESULTS
During 14 years of follow-up, we documented 658 incident cases of nonfatal MI and 281 cases of fatal CHD. After controlling for cardiovascular risk factors, including smoking and hypertension and intake of alcohol, fiber, vitamin E, and saturated, polyunsaturated, and trans fat, the relative risks (RRs) of CHD between extreme quintiles were 0.69 (95% confidence interval [CI], 0.55-0.87) for folate (median intake, 696 microg/d vs 158 microg/d) and 0.67 (95% CI, 0.53-0.85) for vitamin B6 (median intake, 4.6 mg/d vs 1.1 mg/d). Controlling for the same variables, the RR was 0.55 (95% CI, 0.41-0.74) among women in the highest quintile of both folate and vitamin B6 intake compared with the opposite extreme. Risk of CHD was reduced among women who regularly used multiple vitamins (RR=0.76; 95% CI, 0.65-0.90), the major source of folate and vitamin B6, and after excluding multiple vitamin users, among those with higher dietary intakes of folate and vitamin B6. In a subgroup analysis, compared with nondrinkers, the inverse association between a high-folate diet and CHD was strongest among women who consumed up to 1 alcoholic beverage per day (RR =0.69; 95% CI, 0.49-0.97) or more than 1 drink per day (RR=0.27; 95% CI, 0.13-0.58).


CONCLUSIONS
These results suggest that intake of folate and vitamin B6 above the current recommended dietary allowance may be important in the primary prevention of CHD among women.
Rimm
E B
EB
Department of Epidemiology, Harvard School of Public Health, Boston, Mass 02115, USA. eric.rimm@channing.harvard.edu
Willett
W C
WC
Hu
F B
FB
Sampson
L
L
Colditz
G A
GA
Manson
J E
JE
Hennekens
C
C
Stampfer
M J
MJ
D000328:Adult; D015331:Cohort Studies; D003327:Coronary Disease / Q000453:epidemiology* / Q000401:mortality; D019587:Dietary Supplements; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D016015:Logistic Models; D008875:Middle Aged; D015999:Multivariate Analysis; D009203:Myocardial Infarction / Q000453:epidemiology*; D009749:Nutrition Surveys; D009752:Nutritional Status; D011446:Prospective Studies; D011736:Pyridoxine / Q000008:administration & dosage; D012306:Risk
D005492:Folic Acid; D011736:Pyridoxine